Element Stiffness Matrix and Equivalent Stiffness of Beam with Reduced Beam Section Connection in Steel Frames

摘要

Reduced beam section connection (RBS) can make plastic hinge away from the beam and column interface,improve ductility of the structure and reach the purpose of seismic design of the connections. Element stiffness matrix and e quivalent stiffness of the beam with RBS were derived using energy method, and then internal forces were analyzed by example. The results show that all the stiffness matrix terms decrease than that of ordinary connections, the re duction is relative to the location and dimensions of the cut; The beam flange reductions have main effect on beam stiffness, relatively small effect on internal force, so the paper suggests that simplified calculation just consider chan ges in stiffness and ignore the effect of changes in internal force, so can analyze static and dynamic problem of the beam with cuts using equivalent stiffness.